Support initialization of incomplete array with zero size (as

  extension).


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@54946 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 10 insertions, 11 deletions

diff --git a/lib/Sema/SemaInit.cpp b/lib/Sema/SemaInit.cpp
index 7c48a110b2..12ca3820dd 100644
--- a/lib/Sema/SemaInit.cpp
+++ b/lib/Sema/SemaInit.cpp
@@ -257,19 +257,18 @@ void InitListChecker::CheckArrayType(InitListExpr *IList, QualType &DeclType,
   }
   if (DeclType->isIncompleteArrayType()) {
     // If this is an incomplete array type, the actual type needs to
-    // be calculated here
+    // be calculated here.
     if (numElements == 0) {
-      // Sizing an array implicitly to zero is not allowed
-      // (It could in theory be allowed, but it doesn't really matter.)
+      // Sizing an array implicitly to zero is not allowed by ISO C,
+      // but is supported by GNU.
       SemaRef->Diag(IList->getLocStart(),
-                    diag::err_at_least_one_initializer_needed_to_size_array);
-      hadError = true;
-    } else {
-      llvm::APSInt ConstVal(32);
-      ConstVal = numElements;
-      DeclType = SemaRef->Context.getConstantArrayType(elementType, ConstVal, 
-                                                       ArrayType::Normal, 0);
+                    diag::ext_typecheck_zero_array_size);
     }
+
+    llvm::APSInt ConstVal(32);
+    ConstVal = numElements;
+    DeclType = SemaRef->Context.getConstantArrayType(elementType, ConstVal, 
+                                                     ArrayType::Normal, 0);
   }
 }
 
diff --git a/test/Sema/array-init.c b/test/Sema/array-init.c
index 7aecdda40e..24a0070c1f 100644
--- a/test/Sema/array-init.c
+++ b/test/Sema/array-init.c
@@ -158,7 +158,7 @@ void charArrays()
   char c3[5] = { "Hello" };
   char c4[4] = { "Hello" }; //expected-warning{{initializer-string for char array is too long}}
 
-  int i3[] = {}; //expected-error{{at least one initializer value required to size array}} expected-warning{{use of GNU empty initializer extension}}
+  int i3[] = {}; //expected-warning{{zero size arrays are an extension}} expected-warning{{use of GNU empty initializer extension}}
 }
 
 void variableArrayInit() {